code.octet-stream.net Git - netwatcher/blob - src/lib.rs

   1 use std::{
   2     collections::{HashMap, HashSet},
   3     net::{IpAddr, Ipv4Addr, Ipv6Addr},
   4     ops::Sub,
   5 };
   6
   7 #[cfg_attr(windows, path = "list_win.rs")]
   8 #[cfg_attr(unix, path = "list_unix.rs")]
   9 mod list;
  10
  11 #[cfg_attr(windows, path = "watch_win.rs")]
  12 #[cfg_attr(target_vendor = "apple", path = "watch_mac.rs")]
  13 #[cfg_attr(any(target_os = "linux", target_os = "android"), path = "watch_linux.rs")]
  14 mod watch;
  15
  16 type IfIndex = u32;
  17
  18 /// Information about one network interface at a point in time.
  19 #[derive(Debug, Clone, PartialEq, Eq)]
  20 pub struct Interface {
  21     pub index: u32,
  22     pub name: String,
  23     pub hw_addr: String,
  24     pub ips: Vec<IpAddr>,
  25 }
  26
  27 impl Interface {
  28     /// Helper to iterate over only the IPv4 addresses on this interface.
  29     pub fn ipv4_ips(&self) -> impl Iterator<Item = &Ipv4Addr> {
  30         self.ips.iter().filter_map(|ip| match ip {
  31             IpAddr::V4(v4) => Some(v4),
  32             IpAddr::V6(_) => None,
  33         })
  34     }
  35
  36     /// Helper to iterate over only the IPv6 addresses on this interface.
  37     pub fn ipv6_ips(&self) -> impl Iterator<Item = &Ipv6Addr> {
  38         self.ips.iter().filter_map(|ip| match ip {
  39             IpAddr::V4(_) => None,
  40             IpAddr::V6(v6) => Some(v6),
  41         })
  42     }
  43 }
  44
  45 /// Information delivered via callback when a network interface change is detected.
  46 ///
  47 /// This contains up-to-date information about all interfaces, plus a diff which
  48 /// details which interfaces and IP addresses have changed since the last callback.
  49 #[derive(Debug, Clone, PartialEq, Eq)]
  50 pub struct Update {
  51     pub interfaces: HashMap<IfIndex, Interface>,
  52     pub diff: UpdateDiff,
  53 }
  54
  55 /// What changed between one `Update` and the next.
  56 #[derive(Debug, Clone, PartialEq, Eq, Default)]
  57 pub struct UpdateDiff {
  58     pub added: Vec<IfIndex>,
  59     pub removed: Vec<IfIndex>,
  60     pub modified: HashMap<IfIndex, InterfaceDiff>,
  61 }
  62
  63 /// What changed within a single interface between updates, if it was present in both.
  64 #[derive(Debug, Clone, PartialEq, Eq, Default)]
  65 pub struct InterfaceDiff {
  66     pub hw_addr_changed: bool,
  67     pub addrs_added: Vec<IpAddr>,
  68     pub addrs_removed: Vec<IpAddr>,
  69 }
  70
  71 /// Errors in netwatcher or in one of the underlying platform integratinos.
  72 #[derive(Debug, Clone, PartialEq, Eq)]
  73 pub enum Error {
  74     // TODO: handle all cases with proper sources
  75     Internal,
  76 }
  77
  78 #[derive(Default, PartialEq, Eq)]
  79 struct List(HashMap<IfIndex, Interface>);
  80
  81 impl List {
  82     fn diff_from(&self, prev: &List) -> UpdateDiff {
  83         let prev_index_set: HashSet<IfIndex> = prev.0.keys().cloned().collect();
  84         let curr_index_set: HashSet<IfIndex> = self.0.keys().cloned().collect();
  85         let added = curr_index_set.sub(&prev_index_set).into_iter().collect();
  86         let removed = prev_index_set.sub(&curr_index_set).into_iter().collect();
  87         let mut modified = HashMap::new();
  88         for index in curr_index_set.intersection(&prev_index_set) {
  89             if prev.0[index] == self.0[index] {
  90                 continue;
  91             }
  92             let prev_addr_set: HashSet<&IpAddr> = prev.0[index].ips.iter().collect();
  93             let curr_addr_set: HashSet<&IpAddr> = self.0[index].ips.iter().collect();
  94             let addrs_added: Vec<IpAddr> = curr_addr_set
  95                 .sub(&prev_addr_set)
  96                 .iter()
  97                 .cloned()
  98                 .cloned()
  99                 .collect();
 100             let addrs_removed: Vec<IpAddr> = prev_addr_set
 101                 .sub(&curr_addr_set)
 102                 .iter()
 103                 .cloned()
 104                 .cloned()
 105                 .collect();
 106             let hw_addr_changed = prev.0[index].hw_addr != self.0[index].hw_addr;
 107             modified.insert(
 108                 *index,
 109                 InterfaceDiff {
 110                     hw_addr_changed,
 111                     addrs_added,
 112                     addrs_removed,
 113                 },
 114             );
 115         }
 116         UpdateDiff {
 117             added,
 118             removed,
 119             modified,
 120         }
 121     }
 122 }
 123
 124 /// A handle to keep alive as long as you wish to receive callbacks.
 125 ///
 126 /// If the callback is executing at the time the handle is dropped, drop will block until
 127 /// the callback is finished and it's guaranteed that it will not be called again.
 128 ///
 129 /// Do not drop the handle from within the callback itself. It will probably deadlock.
 130 pub struct WatchHandle {
 131     _inner: watch::WatchHandle,
 132 }
 133
 134 /// Retrieve information about all enabled network interfaces and their IP addresses.
 135 ///
 136 /// This is a once-off operation. If you want to detect changes over time, see `watch_interfaces`.
 137 pub fn list_interfaces() -> Result<HashMap<IfIndex, Interface>, Error> {
 138     list::list_interfaces().map(|list| list.0)
 139 }
 140
 141 /// Retrieve interface information and watch for changes, which will be delivered via callback.
 142 ///
 143 /// If setting up the watch is successful, this returns a `WatchHandle` which must be kept for
 144 /// as long as the provided callback should operate.
 145 ///
 146 /// The callback will fire once immediately with an initial interface list, and a diff as if
 147 /// there were originally no interfaces present.
 148 ///
 149 /// This function will return an error if there is a problem configuring the watcher, or if there
 150 /// is an error retrieving the initial interface list.
 151 ///
 152 /// We assume that if listing the interfaces worked the first time, then it will continue to work
 153 /// for as long as the watcher is running. If listing interfaces begins to fail later, those
 154 /// failures will be swallowed and the callback will not be called for that change event.
 155 pub fn watch_interfaces<F: FnMut(Update) + Send + 'static>(
 156     callback: F,
 157 ) -> Result<WatchHandle, Error> {
 158     watch::watch_interfaces(callback).map(|handle| WatchHandle { _inner: handle })
 159 }